Cuban state media announced last summer that cholera had sickened 417 people and killed three. It had been unheard of on the island for years. In January there was another report of 51 cases in Havana.

There has been no word since then about the disease in official media such as Communist Party newspaper Granma.

But state television and posters in clinics have been reminding Cubans of the importance of good hygiene lately, as they typically do during the country’s hot and humid tropical summers, when diarrheic diseases increase.

Last week the United States issued a travel alert for Cuba due to cholera.

Cholera causes severe dehydration that can be fatal, but it is treatable if detected in time.

Cuban medical workers have played an important role in treating the disease in nearby Haiti, where cholera has killed thousands in recent years.